The present invention pertains to particles of preferably anhydrous, magnesium chloride (MgCl.sub.2) in a new form as well as the process for their fabrication which overcome the disadvantages of spherical forms of MgCl.sub.2. These MgCl.sub.2 particles can be employed as catalytic supports, particularly in Ziegler-Natta catalytic components. When these catalytic components are employed as part of a catalyst system in the polymerization of olefins, they preserve the morphology of the support. These catalytic components, catalyst systems utilizing the same are also part of the invention as are the processes for making these products and polyolefins obtained by the use of the catalytic components.